Fungicidal plant protection



eral formula:

United States Patent 3,097,132 FUNGICIDAL PLANT PROTECTION Christian Wiegand, Wuppertal-Elherfeld, and Ferdinand Grewe, Cologne-Stammheim, Germany, asiwors to Farbenfabriken Bayer Aktiengeselischaft, Leverkusen, Germany, a corporation of Germany No Drawing. Filed Oct. 4, 1960, Ser. No. 60,289 Claims priority, application Germany Oct. 10, 1959 6 Claims. (Cl. 167-33) The present invention relates to and has as its objects new and useful fungicidal plant protecting agents and methods of combating fungi therewith. The compounds which were found to be of value to destroy damaging fungi of plants may be represented by the following gen- R, on, X

e.g., German Patent 1,040,752.)

Furthermore it is known from US. Patent 2,782,204 that certain 1,3-di-higher-alkyl-benzimidazoline-bromides possess fungicidal properties which make them useful in the field of disinfection. It is also known from J. Pharm. Soc. Japan, vol. 63 (1943), pp. 593-559, that certain 1-higher-alkyl-3-lower-alky1-benzimidazoline salts may be used as inert soaps and that some of the compounds mentioned in the aforementioned journal also possess bactericidal action useful in the field of disinfection.

All these compounds, however, were as yet not used for the protection of living plants, because they damage them or because their effect is only of short duration.

In accordance with the present invention it has been found that insoluble salts of l-lower alkyl-3-higher alkylbenzimidazoles, even the salts of hydrohalic acids, are usable for the treatment of living plant cultures. In cold Water these last mentioned salts are also only difficultly soluble.

Besides the aforementioned hydrohalic acid salts, salts of other acids are naturally also suitable which are difficul-tly soluble or insoluble in cold water.

Most specifically compounds of the above said formula are useful against fungicidal attack in which the ion X is chloride, bromide, sulfate, nitrate and the like. More complex ions very useful for the above described invention are:

[F 9 (ON) a] Hexacyanoferrate [Cr (CNS) 4.2NH3J9 Reineckate ice S O z Naphthaline-1,5-disulfonate (Di) -nitrophenyl-sulfonate Pentachloro-phenate 2-mercaptobenzhnidazolate @iN\C S 6 S/ 2-mercapto-benzothiazolate and other similar groups which render the above shown lower alkyl, higher 'alkyl benzimidazoles diflicultly watersoluble or water-insoluble.

The groups R -R of the formula of the beginning of this application more specifically are:

R and R lower lalkyls up to 4 carbon atoms, R may also be hydrogen, R higher alkyls between 8 and 20 carbon atoms, and R, such groups as lower alkyl, lower alkoxy, nitro, chlorine, bromine and the like.

The compounds according to the invention are effective against a series of phytopathogenic fungi, of which Phytophthora infestans Alternaria solani Plasmopara viticola Venturi inaequalis are principally to be mentioned, without thereby limiting the action of these fungi.

EXAMPLES The fungicidal activity of the compounds to be used according to the invention are illustrated by way of example by 1-methyl-3-dodecyl-benzimidazolium salts and Phytophthora infestans:

Young tomato plants (Bonny Best) are sprayed with aqueous emulsions formed by mixing the active ingredient of the preparations in the stated concentrations. Auxiliary solvents (equal parts) such as dimethyl formamide, chlorobenzene, acetone and the like are useful .to prepare these emulsions and a non-ionic emulsifier of the type arylhydroxypolyglycolether may be used, too,

' at l820 C. and a relative humidity of 98% to 100%.

The casualty rate of the treated plants is given in percent of the casualty rate of the untreated controls whose casualty rate is taken as 100. Untreated plants are at the moment of evaluation completely destroyed by the fungus.

Table 1.-Phytophthora infestans/tomtztoes Casualty rate at preparation concentrations in 7 Preparation percent N t I CH BI 15 32 42 r f t C H: l- 5 N:

\ SOa OH I 41 T CH: NO:

CH [F8(CN)0] l3 33 1 To C J l" llnHrs N C--CH: [FMCNM] 6 36 If u CH; J3

Untreated control 100 The compounds useful according to this invention can be sprayed in a dispersed or emulsified form or also be applied in dry form or as dusts. In the case of application as a spraying medium they are ground with suitable wetting and dispersing agents in the presence of inert materials (such as kaolin, talc or similar substances) or, together with emulsifiers, dissolved in suitable solvents.

Their continued application with other (even inorganic) fungicides and/ or insecticides is possible.

We claim:

1. A method for protecting plants against fungicidal attack comprising treating the plants with a salt of 1- lower aIkyI-B-higher':alkylbenzimidazole of the following formula I Q t t l 4 2. A method for protecting plants against fungicidal attack comprising treating the plants with a salt of l- 7 lower alkyl-3-higher alkylbenzimidazole of the following formula:

t l0 1 i 3. A method for protecting plants against fungicidal attack comprising treating the plants with a salt of 1- 15 lower alkyl-'3-higher alkylbenzimidazole of the following formula:

9 H on [Fe(CN)o] V (EH3 3 4. A method for protecting plants against fungicidal attack comprising treating the plants with a. salt of 1- lower alkyl-3-higher alkylbenzimidazole of the following formula:

7 c-0H3 [FewNn] to 5. A method for protecting plants against fungicidal attack comprising treating the plants with a salt of 1- lower alkyl-3-higher alkyl-benzirnidazole having the following formula:

R4- 7 CR1 X R1" in which R stands for a lower alkyl radical having up to 4 carbon atoms; R stands for a member selected from the group consisting of hydrogen and lower alkyl radical having up to 4 carbon atoms; R stands for a higher alkyl radical having from 8 to 20 carbon atoms; R; stands for a member selected from the group consisting of hydrogen, lower alkyl, lower alkoxy, chlorine, and nitro; and X is a salt-forming anion selected from the *group consisting of chloride, bromide, sulfate, nitrate, hexacyanoferrate, reineckate, naphthalene-1,5-disulfonate, nitrophenyl-sulfonate, di-nitrophenyl-sulfonate, pentachlorophenate, Z-mercapto-benzomidazolate and Z-mercapto-benzothiazolate.

6. A fungicidal composition comprising (a) A salt of a l-lower alkyl-3-higher alkyl-benzimidazole'of the following formula:

N t- V P I on, X (0 in which R stands for lower alkyl radicals having up to 4 carbon atoms; R stands for a member 6 selected from the group consisting of hydrogen and (0) water, and lower alkyl radicals having up to 4 carbon atoms; (d) an auxiliary solvent selected from the group con- R stands for a higher alkyl radical having from 8 sisting of dimethyl formamide, chlorobenzene and to 20 carbon atoms; R; stands for a member seace-tone.

lected from the group consisting of hydrogen, lower 5 alkyl, lower alkoxy, chlorine, and nitro; and X is References Clted m the file of this patent a salt-forming ion selected from the group consist- UNITED TES PATENTS ing of chloride, bromide, sulfate, nitrate, heXa- 2,782,204 Tenenbaum Feb. 19, 1957 cyanoferrate, reineckate, naphthalene-1,5-disulfonate, 2,376,233 H li et 1 3, 1959 ni-trophenyl-sulfonate, di-nitrophenyl-sulfona-te penta 10 chlorophenate, Z-mercapto-benzimidazolate, 2-mer- FOREIGN PATENTS capto-benzothiazolate, 535,065 Belgium Nov. 21, 1958 (b) a non-ionic emulsifier, 601,091 Canada July 5, 1960 

6. A FUNGICIDAL COMPOSITION COMPRISING (A) A SALT OF A 1-LOWER ALKYL-3-HIGHER ALKYL-BENZIMIDAZOLE OF THE FOLLOWING FORMULA: 